BIOCHEMISTRY
Nishimura, S., Harada, F., Narushima, V., and Seno, T. (1967), Biochim. Biophys. Acta 142, 133. Ofengand, E. J., Dieckmann, M., and Berg, P. (1961), J . Biol. Chem. 236,1741. Otaka, E., and Osawa, S. (1960), Nature 185,321, Petrovic, J., and Petrovic, S. (1966), Anal. Biochem. 15, 187. Rajbhandary, U. L., Chang, S. H., Stuart, A,, Faulkner, R. D., Hoshinson, R. M. and Khorana, H. G . (1967), Proc. Natl. Acad. Sci. U. S . 57,751. Schachman, H. K. (1959), Ultracentrifugation i n Biochemistry, New York, N. Y . ,Academic. Singer, B., and Fraenkel-Conrat, H. (1962), Biochemistry I, 852. Spirin, A. S. (19631, Progr. Nucleic Acid Res. I, 301.
Sueoka, N., and Cheng, T. Y . (1962), J . Mol. Biol. 4 , 161. Tissikres, A. (1959), J . Mol. Bid. I, 365. Wacker, W. E. C., Gordon, M. P., and Huff, W. (1963), Biochemistry 2,716. Wacker, W. E. C., and Vallee, B. L. (1959), J . Biol. Chem. 234, 3257. Watson, J. D., and Ralph, R. K. (1966), J . Mol. Bid. 22,67. Wicks, W. D., Greenman, D. L., and Kenney, F. T. (1965), J. Biol. Chem. 240,4417. Zachau, H., Dutting, D., and Feldman, H. (1966), Angew. Chem. 78,392. Zubay, G. (1962), J . Mol. Biol. 4,347.
Biosynthesis of Ubiquinones by Malarial Parasites. I. Isolation of [ '*C]Ubiquinones from Cultures of Rhesus Monkey Blood Infected with Plasmodium knowlesi" Frederick S. Skelton,? Kenneth D. Lunan, Karl Folkers,? Jerome V. Schnell, Wasim A. Siddiqui. and Quentin M. Geiman
It has been demonstrated that Plasmodium knowlesi biosynthesizes [ 14C]ubiquinones-8, -9, and perhaps -7 from [ 4C]p-hydroxybenzoic acid by the isolation of these ubiquinones from parasitized (P. knowlesi) rhesus monkey blood cells cultured in ABSTRACT:
T
he occurrence of ubiquinones-8 and -9 (I, n = 8 and 9, respectively) in duck blood infected with Plasmodium lophurae, in contrast to only ubiquinone-10 (I, n = 10) in normal duck blood, has been reported (Rietz et al., 1967). A similar analysis (F. S. Skelton, P. J. Rietz, and K. Folkers, 1968, unpublished data) performed on rhesus monkey blood infected with either Plasmodium knowlesi or Plasmodium cynomolgi
synthetic medium containing [14C]p-hydroxybenzoic acid. Only [14C]ubiquinone-10was isolated from control cultures of unparasitized rhesus monkey blood cells and was shown to be associated with the leucocytes.
also showed only ubiquinone-10 in the normal blood and ubiquinones-8 and -9 in the infected blood. 0
cH30@cH' CH30
YHJ (CH,CH =CCH,),H
0
I
1284
* From the Stanford Research Institute, Menlo Park, California 94025 (F. S. S., K. D. L., and I
